Fuel additive formulation and method of using same

ABSTRACT

An improved fuel additive formulation, method of use, and method of producing the fuel formulation are described. The improved fuel additive of the present invention comprises a mixture of nitroparaffins (comprising nitromethane, nitroethane, and nitropropane), and a combination of modified commercially available ester oil and/or a solubilizing agent, and/or toluene. The ratio of ester oil and/or solubilizing agent and/or toluence to nitroparaffin is preferably less than 20 volume percent, with nitroparaffins comprising the balance of the additive. A method of preparing and using the additive formulation is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application relates to, is entitled to the benefit of theearlier filing date and priority of, and is a national application filedunder 35 U.S.C. § 371 of prior international patent applicationPCT/US01/23604 filed Jul. 27, 2001, that is a Continuation-in-Part of,relates to, and is entitled to the benefit of the earlier filing dateand priority of, application Ser. No. 09/628,020 filed on Jul. 28, 2000,now U.S. Pat. No. 6,319,294, which are herein incorporated by referenceas if fully set forth.

FIELD OF THE INVENTION

The present invention relates to an improved fuel additive formulationfor internal combustion engines, and method of making and using thesame. The fuel additive of the present invention provides an improvedmotor fuel, particularly for automobiles. The formulation of the presentinvention is useful in either gasoline- or diesel-fueled engines, and inautomobiles, trucks, and various other engine applications. In apreferred embodiment, the invention is an additive formulation, andmethod of making and using the formulation, to reduce emissions, improveperformance and environmental health and safety, and reduce the risks oftoxic substances associated with motor fuels.

BACKGROUND OF THE INVENTION

For some time, various companies and persons have worked to improve theperformance and reduce the adverse environmental effects of internalcombustion engines. As the increased use of automobiles in the UnitedStates has offset reductions in auto emissions, legislators, regulators,the petroleum and automobile industries and various other groups havesought new ways to address air pollution from cars. As part of thateffort, these groups have increasingly focused on modification of fuelsand fuel additives. Perhaps the best known fuel modification relating toair pollution control is the elimination of lead, used as an antiknockcompound, from gasoline.

The 1990 amendments to the Clean Air Act contain a new fuels program,including a reformulated gasoline program to reduce emissions of toxicair pollutants and emissions that cause summer ozone pollution, and anoxygenated gasoline program to reduce carbon monoxide emissions in areaswhere carbon monoxide is a problem in winter. Environmental agencies,such as the United States Environmental Protection Agency (EPA) and theCalifornia Air Resources Board (CARB), have promulgated variousregulations compelling many fuel modification efforts. A coalition ofautomobile manufacturers and oil companies has extensively reviewed thetechnology for improving fuel formulations and produced what has beenreferred to as the “Auto/Oil” study. The data from the Auto/Oil studyhas formed the basis for some regulatory approaches, such as CARB'smatrix of acceptable gasoline formulations.

With respect to the oxygenated gasoline program, the most commonly usedoxygenates are ethanol, made from biomass (usually grain or corn in theUnited States), and methyl tertiary butyl ether (MTBE), made frommethanol that is usually made from natural gas. Oxygenates such asethanol and MTBE increase a fuel's octane rating, a measure of itstendency to resist engine knock. In addition, MTBE mixes well withgasoline and is easily transported through the existing gasolinepipeline distribution network. See, American Petroleum Institutewebsite: Issues and Research Papers (http://www.api.org/newsroom.cgi)“Questions About Ethanol” and “MTBE Questions and Answers”; and“Achieving Clean Air and Water: The Report of the Blue Ribbon Panel onOxygenates in Gasoline” which are incorporated herein by reference.

Reformulated gasoline has been blended to reduce both exhaust andevaporative air pollution, and to reduce the photochemical reactivity ofthe emissions that are produced. Reformulated gasoline is certified bythe Administrator of the EPA and must include at least two percent (2%)oxygenate by weight (the so-called “oxygen mandate”). Ethanol and MTBEare both used in making reformulated gasoline.

Both ethanol (as well as other alcohol-based fuels) and MTBE havesignificant drawbacks. Ethanol-based fuel formulations have failed todeliver the desired combination of increased performance, reducedemissions, and environmental safety. They do not perform substantiallybetter than straight-run gasoline and increase the cost of the fuel.

Adding either ethanol or MTBE to gasoline dilutes the energy content ofthe fuel. Ethanol has a lower energy content than MTBE, which in turnhas a lower energy content man straight-run gasoline. Ethanol has onlyabout 67% the energy content of the same volume of gasoline and it hasonly about 81% of the energy content of an equivalent volume of MTBE.Thus, more fuel is required to travel the same distance, resulting inhigher fuel costs and lower fuel economy. In addition, the volatility ofthe gasoline that is added to an ethanol/gasoline blend must be furtherreduced in order to offset the increased volatility of the alcohol inthe blend.

Ethanol has not proven cost effective, and is subject to restrictedsupply. Because of supply limitations, distribution problems, and itsdependence on agricultural conditions, ethanol is expensive. TheAmerican Petroleum Institute reports that, in 1999, ethanol was abouttwice the cost of an energy equivalent amount of gasoline. The politicsof agriculture also effect ethanol supply and price.

Ethanol also has a much greater affinity for water than do petroleumproducts. It cannot be shipped in petroleum pipelines, which invariablycontain residual amounts of water. Instead, ethanol is typicallytransported by truck, or manufactured where gasoline is made. Ethanol isalso corrosive. In addition, at higher concentrations, the engine mustbe modified to use an ethanol blend.

Ethanol has other drawbacks as well. Ethanol has a high vapor pressurerelative to straight-run gasoline. Its high vapor pressure increasesfuel evaporation at temperatures above 130° Fahrenheit, which leads toincreases in volatile organic compound (VOC) emissions. EPA hasconcluded that VOC emissions would increase significantly with ethanolblends. See, Reformulated Gasoline Final Rule, 59 Fed. Reg. 7716, 7719(1994).

Finally, although much research has focused on the health effects ofethanol as a beverage, little research has addressed ethanol's use as afuel additive. Nor has ethanol been evaluated fully from the standpointof its environmental fate and exposure potential.

MTBE has its share of drawbacks as well. MTBE was first added togasoline to boost the octane rating. In line with the 1990 Clean Air Actamendments, MTBE was added in even larger amounts as an oxygenate toreduce air pollution. Unfortunately, MTBE is now showing up as acontaminant in groundwater throughout the United States as a result ofreleases (i.e., leaking underground gasoline storage tanks, accidentalspillage, leakage in transport, automobile accidents resulting in fuelreleases, etc.).

MTBE is particularly problematic as a groundwater contaminant because itis soluble in water. It is highly mobile, does not cling to soilparticles, and does not decay readily. MTBE has been used as an octaneenhancer for about twenty years. The environmental and health risksposed by MTBE, therefore, parallel those of gasoline. Some sourcesestimate that 65% of all leaking underground fuel storage tank sitesinvolve releases of MTBE. It is estimated that MTBE may be contaminatingas many as 9,000 community water supplies in 31 states. A University ofCalifornia study showed that MTBE has affected at least 10,000groundwater sites in the State of California alone. The full extent ofthe problem may not be known for another ten years. See, “MTBE, to WhatExtent Will Past Releases Contaminate Community Water Supply Wells?, ”ENVIRONMENTAL SCIENCE AND TECHNOLOGY, at 2-9 (May 1, 2000), which isincorporated herein by reference.

EPA also has determined that MTBE is carcinogenic, at least wheninhaled. Other unwelcome environmental characteristics are its foulsmell and taste, even at very low concentrations (parts per billion).Because of these drawbacks, the U.S. Government is considering banningMTBE as a gasoline additive. In September 1999, the EPA recommended thatMTBE use be curtailed or phased out. Several states are planning to haltor reduce MTBE use. California plans to phase it out by 2002, and Mainealready has the EPA's permission to quit using MTBE if it can find otherways of meeting air quality standards. The EPA also has approved NewJersey's request to stop using MTBE in gasoline during the winter.

The environmental threat from MTBE may be even greater than that from anequivalent volume of straight-run gasoline. The constituents of gasolineconsidered most dangerous are the aromatic hydrocarbons: benzene,toluene, ethylbenzene, and xylene (collectively, “BTEX”). The BTEXaromatic hydrocarbons have the lowest acceptable drinking watercontamination limits. Both ethanol and MTBE enhance the environmentalrisks posed by the BTEX compounds, apart from their own toxicity.Ethanol and MTBE act as a co-solvent for BTEX compounds in gasoline. Asa result, the BTEX plume from a source of gasoline contaminationcontaining ethanol and/or MTBE travels farther and faster than one thatdoes not contain either oxygenate.

The BTEX aromatic compounds have relatively lower solubility in waterthan MTBE. BTEX compounds tend to biodegrade in situ when they leak intothe soil and ground water. This provides at least some naturalattenuation. Relative to the BTEX compounds, however, MTBE biodegradesat a significantly lower rate, by at least one order of magnitude, orten times more slowly. Some sources estimate that the time required forMTBE to degrade to less than a few percent of the original contaminantlevel is about ten years.

Other initiatives have involved efforts to formulate a cleanerburning—reformulated —gasoline (RFG). For example, Union Oil Company ofCalifornia (UNOCAL) has secured a number of U.S. patents that covervarious formulations of RFG. Jessup, et al., U.S. Pat. No. 5,288,393,for Gasoline Fuel (Feb. 22, 1994); Jessup, et al., U.S. Pat. No.5,593,567, for Gasoline Fuel (Jan. 14, 1997); Jessup, et al., U.S. Pat.No. 5,653,866, for Gasoline Fuel (Aug. 5, 1997); Jessup, et al., U.S.Pat. No. 5,837,126 for Gasoline Fuel, (Nov. 17, 1998); Jessup, et al.,U.S. Pat. No. 6,030,521 for Gasoline Fuel (Feb. 29, 2000). The UNOCALpatents specify various end points in the blending of gasoline, andpurport to reduce emissions of selected contaminants: Carbon monoxide(CO); Nitric oxides (NOx); Unburned Hydrocarbons (HC); and otheremissions.

UNOCAL has already enforced one of its RFG patents. Union Oil Company ofCalifornia v. Atlantic Richfield, et al., 34 F.Supp.2d 1208 (C.D. Cal.1998); and Union Oil Company of California v. Atlantic Richfield, etal., 34 F.Supp.2d 1222 (C.D. Cal. 1998). The District Court judgmentestablished a substantial royalty rate (5 ¾ cents per gallon) forUNOCAL's patented RFG formulation. This has increased substantially thecost of motor fuels in the affected markets. Although the judgment hasbeen affirmed on appeal, Union Oil Company of California v. AtlanticRichfield, et al., 208 F.3d 989, 54 USPQ2d 1227 (Fed. Cir. 2000), andthe Supreme Court has denied review.

Historically, margins in the refining and marketing of motor fuels tendto be narrow, typically less than cents a gallon. Alexi Barrionuevo,“Stumped at the Pump? Look Deep into the Refinery,” WALL STREET JOURNAL,B1 (May 26, 2000), which is incorporated herein by reference. RFGimposes added costs on refiners. These formulations increase the cost ofthe finished product, relative to straight-run gasoline. Memorandum fromLawrence Kumins, Specialist in Energy Policy, Resources, Science andIndustry Division, Library of Congress, to Members of Congress, “MidwestGasoline Price Increases (Jun. 16, 2000), which is incorporated hereinby reference. UNOCAL's royalty rate of 5¾ cents per gallon imposes asubstantial additional cost burden on RFG.

These various problems have impaired the efficacy or cost-effectivenessof each of these various alternatives. Alcohols have not resolved theperformance and emission needs for improved motor fuels. MTBE imposesunacceptable environmental (soil and groundwater) and public healthproblems. Methyl Teritary Butyl Ether (MTBE), 65 Fed.Reg. 16093 (2000)(to be codified at 40 C.F.R. pt. 755) (proposed Mar. 24, 2000).Reformulated gasoline has been controversial and expensive. Accordingly,there remains a substantial and unmet need for an improved gasolineformulation that enhances (or at least does not impair) performance,while reducing emissions and the environmental and public health risksfrom motor fuels. The present invention satisfies those needs.

The present invention employs a unique combination of nitroparaffins andester oil, to enhance the performance of and reduce emissions frominternal combustion engines and, in particular, automobiles.Nitroparaffins have been used in prior fuel formulations, for differentengine applications, without achieving the results of the presentinvention. For example, nitroparaffins have long been used as fuelsand/or fuel additives in model engines, turbine engines, and otherspecialized engines. Nitromethane and nitroethane have been used byhobbyists. Nitroparaffins have also been used extensively in dragracing, and other racing applications, due to their extremely highenergy content.

The use of nitroparaffins in motor fuels for automobiles, however, hasseveral distinct disadvantages. First, some nitroparaffins are explosiveand, pose substantial hazards. Second, nitroparaffins are significantlymore expensive than gasoline—so expensive as to preclude their use inautomotive applications. Third, nitroparaffins have generally been usedin specialized engines that are very different than automotive engines.Fourth, the high energy content of nitroparaffins requires modificationof the engine, and additional care in transport, storage, and handlingof both the nitroparaffin and the fuel. Further, in some fuelapplications, nitroparaffins have had a tendency to gel. The high cost,and extremely high energy content of nitroparaffins, has precluded theiruse as an automotive fuel. Moreover, the extreme volatility and dangerof explosion from nitromethane taught away from its use as a motor fuelfor automobiles.

Notwithstanding these drawbacks, patents have been issued for fuelformulations containing nitroparaffins. One of these, Michaels, U.S.Pat. No. 3,900,297 for Fuel for Engines (Aug. 19, 1975), describes afuel formulation for engines comprising nitroparaffin compositions.Michaels notes that nitroparaffin formulations have a tendency topre-ignition in reciprocating internal combustion engines. Moreover,Michaels notes that nitroparaffins are not readily miscible inhydrocarbons.

Michaels discloses and claims a formulation that is intended to increasethe solubility of nitroparaffins in hydrocarbons. Michaels claims thatnitroparaffins can be made soluble in gasoline by including a syntheticester lubricating oil. Michaels specifies that any commerciallyavailable gasoline, having a boiling point between 140° to 400° F. issuitable. Michaels asserts that the inclusion of ester lubricating oilat the levels specified by Michaels “would render perfectly miscibleotherwise immiscible nitroalkane/gasoline blends.” Michaels '297 patent,at Col. 2, 11. 27-28.

Michaels expressly notes that one of the advantages of including esterlubricating oil in his invention is to provide upper cylinderlubrication: “[i]nclusion of ester lubricant in fuel compositions forreciprocating combustion engines has the further advantage of providinginternal lubrication within the engine, thereby reducing engine wear andimproving engine efficiency.” Michaels, '297 patent at Col. 2, 11.31-35. “Ester lubricants of the type suitable for use in the fuelcompositions of the present [Michaels'] invention include those whichhave found wide use as “synthetic oil” in modern jet engines. Theseinclude the commercially available synthetic lubricating oils metting[sic] Military Specifications MIL-L-7808 and MIL-L-9236 of the estertype. Specific examples of commercially available synthetic oilssuitable for use in the compositions of the present invention includeTexaco SATO No. 7730 Synthetic Aircraft Turbine Oil, Monsanto SkylubeNo. 450 Jet 20 Engine Oil, and [Mobil] II Turbine Oil.” Michaels '297patent, at Col. 3, 11. 11-21. Michaels describes the chemicalformulations of various ester oils, Michaels '297 patent, at Col. 3, 11.11 to Col. 6, 11. 42, which discussion is incorporated herein byreference. The ester lubricating oils of the present invention include,without limitation, those described by Michaels in his '297 patent aswell as any other ester oils that may be suitable to achieve the objectsof the present invention.

Michaels expressly notes that: “[c]ommercially available ester oils ofthe above description usually contain additives to improve theirperformance as lubricants, which additives do not ordinarily adverselyaffect performance of such oils in my [Michaels'] fuel compositions. Ingeneral, for reasons of ready availability, use of ester oil in the formof commercially available synthetic ester turbine oils is preferred.”Michaels '297 patent, at Col. 4, 11. 44-50. Michaels not only includesthe additives normally found commercially in such ester oils, heexpressly prefers them.

Among those additives typically included in commercially available esteroils are flame retardants. These flame retardants inhibit the combustionof the oil, without impairing the miscibility of the nitroparaffins,allowing the ester oil to lubricate the upper cylinder.

Michaels specifies that: “[t]he ester oil is preferably employed inminimum amount required to provide a homogeneous liquid fuelcompositions [sic]. Use of less than that amount results innon-homogeneous compositions, with concomitant physical separation ofliquid components into layers, and use of excess amounts of ester oil iswasteful and may result in excess carbon deposition within the engine,fouling of sparkplugs and generally unsatisfactory engine operation. Nogeneral rule can be set down fixing precise amounts of ester oilrequired to achieve homogeneity of the compositions, since that amountdepends on variables such as the type of gasoline, nitroalkane and esteroil, as well as the proportions in which gasoline and nitroalkane areincorporated into the composition . . . As a general guide, use of esteroil in proportions of from 1 to 4 parts of ester oil to 8 parts ofnitroalkane will ordinarily provide a homogeneous blend.” Michaels '297patent, at Col. 5, 11. 47 to Col. 6, 11. 2.

Michaels' only disclosure of making the additive or fuel relates to howto determine the appropriate amount of ester oil to provide ahomogeneous blend: “the required amounts of ester oil are readilydetermined by simple experimentation of a routine nature, e.g. by firstadding the nitroalkne to the gasoline in desired amount, then adding theester oil in small portions, followed by thorough mixing after eachaddition, until a homogeneous blend is obtained.” Michaels, '297 patent,at Col. 5, 11. 61-66. In contrast, both the process of the presentinvention and the product obtained by the present process, are differentthan Michaels.

Michaels claims that his invention improves combustion efficiency:“[t]he advantages of using the fuel of the present invention are foundin lower fuel consumption due to high BTU of energy developed resultingin higher horsepower output and cleaner burning, since the added blends(of nitroalknes and their mixtures) improve combustion efficiency,”Michaels '297 patent at Col. 6, 11. 29-34, in conjunction with glow plugengines. Michaels speculates that “[t]he same advantages may occur whenthis fuel is used in other internal combustion engines or jet engines.”Michaels '297 patent, at Col. 6, 11. 34-36. Yet, Michaels provides nodata to support this conjecture. Nor does Michaels identify any increasein horsepower or reduction in emissions, apart from high BTU content andhigher fuel efficiency of Michaels' fuel.

Michaels claims a fuel comprising from 5 to 95% (volume) gasoline and 95to 5% additive. Michaels' additive, in turn, comprises from 10 to 90%nitroparaffin and 90 to 10% ester lubricating oil. Michaels claims thathis fuel is a homogeneous blend of additive and gasoline. He attributeshis results to the ability of the ester lubricating oil to make thenitroparaffin soluble in gasoline. Michaels' components are a blend anddo not react with one another. They are a simple mixture.

The present inventors are not aware that the formulation described andclaimed by Michaels has ever been used as a motor fuel for automobiles.Although Michaels sold a fuel additive for automobiles, the presentinventors believe that the additive Michaels sold may have beendifferent than the additive disclosed in Michaels' '297 patent.

Michaels' fuel comprises 0.5 to 81.5 volume percent nitroalkane. Atlevels this high, Michaels' formulation teaches strongly away fromautomotive applications. The energy content of the nitroalkanes issimply too high for automotive use. Michaels himself provided examplesof only model engines, turbine, jet engine, and other specializedapplications. Nor would Michaels have been understood by persons ofordinary skill in the art as suggesting a viable automotive fuel. Highnitroalkane levels would likely damage or destroy an automotive engine.

The cost of Michaels' additive is substantially higher than the cost ofgasoline. At a concentration of even 5 volume percent, the cost of thefinished formulation blended according to Michaels' teachings would bemultiples, if not orders of magnitude, higher than the cost of anequivalent volume of gasoline. At higher concentrations, which Michaelsteaches may range up to 95 volume percent, the cost is prohibitive.Michaels' fuel is not cost-effective for motor vehicle use.

Prior to 1985, a similar composition was marketed by an individual namedMoshe Tal, through a corporation named TK-7. Mr. Tal sold theformulation as “ULX-15.” From 1985 to March of 1987, Tal supplied aformulation that reportedly was made in accordance with the '297 patent,to a company trading under the name Energex. Energex actively marketedthe product throughout the western United States by advertising it in“outdoor” magazines such as FIELD AND STREAM. Energex principalsattended various events, such as fishing competitions, where on at leastone occasion they demonstrated the Energex/TK-7 product for use infishing boat engines. The Energex/TK-7 formulation enjoyed limited salesonly in a narrow, non-automotive market. Michaels later asserted thatthe Energex/TK-7 formulation was covered by his '297 patent.

The present inventors believe that the Energex/TK-7 formulationcomprised the following composition:

TABLE 1 “Energex/TK-7” Formulation Volume of Formulation Component(Parts of Total) 2-nitropropane 35-38 Nitroethane 3-4 Nitromethane 1-2Mobil Jet II ™ ½-1   Alcohol (methanol or isopropyl) 1-2 Total: 40½-47  

In 1986, an individual identifying himself as Michaels contactedEnergex, and claimed that Energex's additive infringed Michaels' '297patent. A principal of Energex, Don Young, met with Michaels in New Yorkin 1986. Young observed some portions of Michaels' preparation of the'297 additive. Although no mixing process is disclosed in the '297patent, Young understood that the preparation of the '297 compositioninvolved a specific mixing procedure. Energex and Michaels entered intoan agreement whereby Energex continued to sell the formulation.

The present inventors believe that the Energex/TK-7 additive was soldfor both gasoline and diesel-fueled outboard motor engines. One or twogallons of diesel fuel was added to the diesel formulation. The presentinventors are unaware of any performance testing of the Michaelsformulation from this time period (prior to March 1987). In 1987,Energex ran out of money, declared bankruptcy, and stopped selling. TheTK-7 product was not marketed from March of 1987 until about May of1988.

In May of 1988, Young began selling the product in a slightly modifiedform, under the name “PbFree.” PbFree secured product from W. R. Grace,under Michaels' supervision. PbFree sold the formulation as “TGS.” TheTGS formulation of the additive as sold by PbFree was substantially thesame as the Energex/TK-7 formulation:

TABLE 2 PbFree “TGS” Formulation (1988 to 1990) Volume of FormulationComponent (Parts of Total) 2-nitropropane 35-38 Nitroethane 3-4Nitromethane 1-2 Mobil Jet II ™ ½-1   Alcohol (methanol or isopropyl)1-2 Total: 40½-47  Although the present inventors are aware of no performance dataavailable for the Energex/TK-7 formulation that was apparently sold fromprior to 1985 through 1987, performance testing was conducted on thePbFree TGS formulation between 1989 and 1990.

As a general proposition, motor fuel testing is subject to a high degreeof variability, requiring precisely defined test parameters andcontrols. Gasoline is extremely variable in composition. Control of thefuel is essential to securing statistically significant results fromengine performance testing. Annual Book of ASTM Standards 2000, SectionFive: Petroleum Products, Lubricants, and Fossil Fuels, Volume 05.04,Petroleum Products and Lubricants (V): D 5966—latest; American NationalStandards Institute (ANSI), “Automotive Fuels—Diesel—Requirements andTest Methods”, Publication No. SS-EN 590, and “Automotive Fuels—Unleadedpetrol—Requirements and Test Methods,” Publication No. SS-EN 228;Society of Automotive Engineers (SAE), “Automotive Gasolines,”Publication No. J312199807 (July 1998), which are incorporated herein byreference.

Different runs of the same formulation under comparable conditions mayvary by as much as 5-17%, depending on the emission variable beingmeasured. Variability is also inherent in the data collected inperformance testing. Vehicles differ and even the same vehicle varies inperformance from day to day. The variability between “nominallyidentical cars” can be from approximately 10 to 27 percent of the meanvalue, for a repeated number of tests using the same fuel in a number ofsimilar vehicles. The Effects of Aromatics, MTBE, Olefins and T ₉₀ onMass Exhaust Emissions from Current and Older Vehicles—The Auto/OilQuality Improvement Research Program. Society of Automobile Engineers(SAE) Technical Paper Series 912322, International Fuels and LubricantsMeeting and Exposition, Toronto, Canada (Oct. 7-10, 1991), which isincorporated herein by reference. In repeated testing of the samevehicles using the same fuel, results may vary from approximately 5 to17% of the mean value (SAE, 1991). Atmospheric conditions, such ashumidity, may also introduce variability. (SAE, 1991).

The testing of the TGS product between 1989 and 1990 did not satisfyeven these generally accepted requirements for reliability in engineperformance testing. Accordingly, the variability of the TGS test datais expected to be even higher than 5-17%.

Prelimiary testing of the TGS product was conducted by the University ofNebraska and Cleveland State University in 1989 and 1990. Both weresmall “pilot” studies. Both researchers recommended more aggressivetests to validate the initial results. The present inventors believethat such definitive testing was never conducted.

Professor Ronald Haybron of the Department of Physics of the ClevelandState University conducted a preliminary evaluation of the TGS productin 1989. He tested one vehicle and used regular (87 octane) unleadedpump gasoline, rather than a standard fuel formulation, as required bygenerally accepted testing standards. Nor were data measured at the samepoints (for example, at the same engine speeds). These limitations ofprocedure, small sample size, and lack of adequate control preclude anyreliable conclusions being drawn from the Cleveland State study.

The Cleveland State study tested the additive at a concentration of 0.1oz. of additive per gallon of fuel. This is a concentration of additivewell below the levels specified and claimed in Michaels' '297 patent.Michaels discloses an additive concentration of 5 to 95% (6.25 oz. to121.6 oz. per gallon) or more. The Cleveland State test was run outsidethat range. Although the results were not statistically significant,Prof. Haybron claimed an improvement in horsepower of 8 to 20%, andreduced carbon monoxide output of 8 to 10%, well within the variabilityof even a well-controlled study.

Professor Peter Jenkins, of the University of Nebraska, failed toreplicate these results. The University of Nebraska, MechanicalEngineering Department conducted testing on the “TGS Fuel Additive.” TheNebraska testing evaluated the data at the same engine speeds for eachconcentration of additive. However, pump gas (regular 87 octane) wasalso used instead of a controlled, reference fuel. Only two vehicleswere tested. Although some evaluations showed improvement at higherconcentrations of additive (i.e., at 0.5 oz. per gallon), they showedlittle, if any, difference at the lowest concentrations tested (0.1 oz.per gallon). Although Prof. Jenkins claimed that the testing showed a 10to 14% improvement in fuel consumption, those values are well within thevariability of even a well-controlled study. There was little to noimprovement on other parameters.

In 1990, PbFree modified the formulation but continued selling theadditive having the composition identified in Table 3:

TABLE 3 PbFree Formulation (1990 to 1998) Volume of FormulationComponent (Parts of Total) 2-nitropropane 28  Nitroethane 11-15Nitromethane  6-15 Mobil Jet II ™ 1 Total: 46-59The present inventors believe that PbFree attempted to sell the productto leaseway Trucking Company and the Cummins Engines Corporation during1991. At that time, the formulation was supplied by W. R. Grace underMichaels' supervision.

The present inventors believe that PbFree supplied the product to theBrigham Young University (BYU), School of Engineering for testing. Theproduct was provided by Michaels. The present inventors understand thatthe PbFree composition failed to improve performance or reduce emissionsin the BYU tests.

In 1992, Michaels stopped supplying product to PbFree. Young attemptedto replicate Michaels' formulation from publicly available sources, suchas Michaels '297 patent. Young was unable to replicate Michaels'formulation from the '297 patent alone, yet, based upon Young'sobservation of Michaels preparing his additive in 1986, Young determinedthat a special mixing step was necessary. Young experimented withvarious methods—stirring, rolling the components in a closed barrel, and“thermoaeration”—and was able to offer an additive formulation for sale.None of these mixing procedures are disclosed in Michaels' '297 patent.

Young continued making and selling the formulation identified above asthe “PbFree” formulation, until 1998, at which point PbFree ceasedoperations. The present inventors are aware of no testing regarding theperformance of the PbFree formulation during this period. In 1998, Youngbegan selling the additive under the name Envirochem, LLC(“Envirochem”). The Envirochem “EChem” formulation is identified inTable 4:

TABLE 4 Envirochem “EChem” Formulation (1998 to 1999) Volume ofFormulation Component (Parts of Total) Nitropropane (1 or 2) 29Nitroethane 10 Nitromethane 10 Toluene 5 Mobil Jet II ™ 1 Total: 55

In addition to the prior formulations derived from Michaels (namely, theULX-15, TGS, PbFree, and EChem formulation discussed above), otherinventors have disclosed and claimed additives comprising nitroparaffinsand either toluene and/or ester oil. Many of these prior knownformulations, however, were either for use as a model engine fuel orlubricant. See e.g., Brodhacker, U.S. Pat. No. 2,673,793 for ModelEngine Fuel (Mar. 30, 1954); Hartley, U.S. Pat. No. 5,880,075 forSynthetic Biodegradable Lubricants and Functional Fluids (Mar. 9, 1999);and Tiffany, U.S. Pat. No. 5,942,474 for Two-Cycle Ester Based SyntheticLubricating Oil (Aug. 24, 1999). Two patents of which the presentinventors are aware disclose the use of a nitroparaffin and esteroil/toluene formulation for use as a fuel additive: Gorman, U.S. Pat.No. 4,330,304 for Fuel Additive (May 18, 1982); and Simmons, U.S. Pat.No. 4,073,626 for Hydrocarbon Fuel Additive and Process of ImprovingHydrocarbon Fuel Combustion (Feb. 14, 1978).

Gorman discloses a mixture of nitroparaffins, including: nitropropane,nitroethane, nitromethane, and others, at 3-65 weight percent of theadditive. Gorman also discloses formulations in which toluene is presentat a concentration of 74 weight percent, well in excess of the presentinvention, along with propylene oxide, tert-butyl hydroperoxide,nitropropanes 1 and 2, and acetic anhydride. Gorman, '304 Patent, Col.9, 11. 53.

Simmons discloses a mixture of one part iron salts of aromatic nitroacid, 10 to 100 parts nitroparaffin, and a solvent, which may betoluene. Simmons does not disclose the use of ester oil. In some ofSimmons' examples, the salt is added directly to the fuel with nosolvent. In at least two of Simmons' examples, the solvent comprisesabout a quarter of the fuel blend, well in excess of the concentrationsof toluene and/or ester oil in the present invention.

Neither Gorman nor Simmons, nor any of the other known priorformulations, disclose the ranges of nitroparaffins, and ester oiland/or toluene of the present invention, let alone the unique benefitsof the present invention to reduce emissions. Prior known formulationswere made by a different process than the present invention. Many of theprior known formulations are used at higher concentrations in the fuelthan is the present invention. The present invention, however, reducesemissions at lower concentrations of additive. In addition, the presentinvention may be used with a variety of fuels, including: gasoline,gasoline and MTBE, gasoline and ethanol, and gasoline/ethanol/MTBEformulations.

In January 2000, Envirochem's assets were purchased by First StanfordEnvirochem, Inc., trading as Magnum Environmental Technologies, Inc.,the assignee of the present application. The present inventors have madea diligent effort to study and improve upon the prior knownformulations. As a result of these efforts, the present applicants haveinvented a new formulation, and method of producing and using the same.

The present inventors began by investigating the EChem formulation. Astudy conducted by Emission Testing Service (ETS) in January 2000 foundthat, although the EChem formulation performed comparable to or slightlyworse than both a standard unleaded gasoline and standard gasoline plus11% MTBE, it reduced carbon monoxide emissions relative to gasoline,reduced NOx emissions relative to gasoline plus MTBE, and improved fuelefficiency relative to both.

The present invention differs in significant respects from the priorknown formulations, as well as from alcohol-based (ethanol) and MTBEfuel additives, and performs better than prior known formulations. Oneembodiment of the present invention is disclosed in Table 5:

TABLE 5 “MAZ 100” Formulation Volume of Formulation Component (Parts ofTotal) 1-nitropropane 29 Nitroethane 10 Nitromethane 10 Toluene 5Modified Ester Oil Lubricant 1 Total: 55

The present inventors have made a number of specific changes in theformulation and in the method of preparing the composition of thepresent invention. The present inventors believe that these changesproduce the improvements they have observed.

Although prior formulations used 2-nitropropane, or a combination of1-nitropropane and 2, the present inventors preferably remove2-nitropropane from the formulation. 2-nitropropane is a knowncarcinogen. Its removal improves the material handling safety of theproduct.

Unlike the prior known formulations, which employed commerciallyavailable ester oils, the present inventors preferably modify the esteroil to remove, or not to introduce, tricresyl phosphate. Tricresylphosphate is a known neurotoxin. In addition, tricresyl phosphate hasflame retardant properties. The present inventors believe that thismodification allows improved performance of the invention in terms ofreduced emissions, at lower concentrations of additive, particularly oncold start up. It also makes the product safer to handle.

The present inventors preferably add toluene to the formulation. Theinventors believe that toluene may emulsify the nitroparaffins into, ormake the nitroparaffins more soluble in, gasoline and lower emissions.

The present inventors preferably lower the amount of ester oil to levelsbelow most of the known prior additives. This too has been found tolower emissions.

The present inventors preferably lower the concentration ofnitromethane. Nitromethane is also a known neurotoxin. Reduction ofnitromethane reduces toxicity and lowers emissions.

The present invention is preferably employed at a lower overallconcentration in the fuel relative to most prior known formulations.This too lowers emissions and reduces toxicity.

The present invention improves performance, reduces material handlingrequirements, and lowers environmental and public health and safetyrisks, as well as emissions, at concentrations at which priorformulations were either untested, ineffective, or failed to produce theunique combination of benefits of the present invention.

It has not been reliably established that the prior known formulationsprovided any improvement in performance or emissions. The presentinvention, on the other hand, achieves benefits, at low concentrationsof additive. Thus, the present invention meets the long-felt, yetunresolved, need for an environmentally safe, improved fuel additive.None of the prior formulations of which the present inventors are awarereduce emissions, particularly on cold start-up. None of the prior knownformulations suggest the present invention.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide a motor fueladditive that provides improved performance at additive concentrationstypical of known additives, and reduced emissions at lowerconcentrations, while avoiding many of the problems associated withprior known additives and motor fuels.

Another object of the present invention is to provide a motor fuel thatexhibits improved performance relative to prior known motor fuels, whileavoiding many of the problems associated with prior known motor fuels.

A further object of the present invention is to provide a motor fuelthat reduces emissions relative to prior known motor fuels, whileavoiding many of the problems associated with prior known motor fuels.

Yet another object of the present invention is to provide a replacement,or supplement, for oxygenates, such as ethanol and MTBE.

Another object of the present invention is to provide a replacement, orsupplement, for oxygenates, such as ethanol and MTBE, that reducesemissions.

A further object of the present invention is to reduce emissions on coldstart-up.

An additional object of the present invention is to provide an improvedfuel formulation that reduces total hydrocarbon emissions.

Yet another object of the present invention is to provide an improvedformulation that reduces non-methane hydrocarbon emissions.

Another object of the present invention is to provide an improved fuelformulation that reduces carbon monoxide emissions.

A further object of the present invention is to provide an improved fuelformulation that reduces NO_(x) formation.

An additional object of the present invention is to provide an improvedfuel formulation that reduces ozone formation.

Yet another object of the present invention is to reduce the formationof precursors to ozone formation.

Another object of the present invention is to reduce hydrocarbonemissions on cold start up.

A further object of the present invention is to reduce carbon monoxideemissions on cold start up.

An additional object of the present invention is to reduce NOx emissionson cold start up.

Yet another object of the present invention is to reduce ozone formationon cold start up.

Additional objects and advantages of the invention are set forth, inpart, in the description which follows and, in part, will be obviousfrom the description or may be learned by practice of the invention. Theobjects and advantages of the invention will be realized in detail bymeans of the instrumentalities and combinations particularly pointed outin the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph depicting the percent improvement in emissions of afuel comprising the additive of the present invention (MAZ 100) relativeto Indolene, a standard reference fuel.

FIG. 2 is a graph depicting the percent improvement in emissions of afuel comprising the additive of the present invention (MAZ 100) relativeto MTBE.

FIG. 3 is a graph depicting the percent improvement in emissions of afuel comprising the additive of the present invention (MAZ 100) relativeto RFG.

FIG. 4 is a graph depicting the prior art, namely, the percentimprovement in emissions of a fuel comprising MTBE over Indolene, astandard reference fuel.

FIG. 5 is a graph depicting the prior art, namely, the percentimprovement in emissions of RGF relative to Indolene, a standardreference fuel.

FIG. 6 is a graph depicting the percent improvement in emissions offuels comprising the present invention (MAZ 100), and MTBE and RFG ofthe prior art, each relative to Indolene, a standard reference fuel.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises an improved fuel additive formulationand method of making and using the same. As embodied herein, the presentinvention comprises: an additive formulation for fuels, and a fuelcontaining the additive, comprising: nitroparaffin; and ester oil and/ora solubilizing agent and/or aromatic hydrocarbon; said fuel resulting inreduced emissions relative to a fuel not containing said additive whenburned in a boiler, a turbine, or an internal combustion engine.

In another embodiment, the present invention comprises: an additiveformulation for fuels, or a fuel containing the additive, comprising: afirst component, comprising 0 to 99 volume percent nitroparaffin,selected from the group consisting of: 1-nitropropane, 2-nitropropane,nitroethane, and nitromethane; a second component, substantiallycomprising the balance of the additive formulation, selected from thegroup consisting of: ester oil lubricant, and/or a solubilizing agentwith at least one chemically relatively polar end and at least onechemically relatively non-polar end, and an aromatic hydrocarbon; theadditive formulation reducing emissions of one or more of the emissionsselected from the group comprising: total hydrocarbons, non-methanehydrocarbons, carbon monoxide, NO_(x), and ozone precursors. Thearomatic hydrocarbon may include, but is not limited to, an alaphaticderivative of benzene, benzene, xylene, or toluene.

In a further embodiment, the present invention comprises: an additiveformulation for motor fuels, and a fuel containing the additive,comprising: from about 10 to about 30 volume percent nitromethane; fromabout 10 to about 30 volume percent nitroethane; from about 40 to about60 volume percent 1-nitropropane; from about 2 to about 8 volume percenttoluene; and from about 1 to about 3 volume percent modified ester oil,or a solubilizing agent.

In yet another embodiment, the present invention comprises: a method ofpreparing a fuel additive formulation, comprising: in a mixing vesseladding about 1 part modified ester oil that is substantially tricresylphosphate-free or a solubilizing agent; adding about 5 parts toluene;allowing said ester oil or said solubilizing agent and said toluene tostand for about 10 minutes at ambient temperature and pressure; addingabout 10 parts of nitromethane to said ester oil or said solubilizingagent and toluene mixture; adding about 10 parts of nitroethane to saidmixture; adding about 29 parts 1-nitropropane to said mixture; andaerating said mixture gently, through a narrow gauge tube at lowpressure, and ambient temperature. As embodied herein, the inventionalso comprises an additive made by the method of the present invention.The invention further comprises a fuel comprising an additive made bythe method of the present invention, as well as the use of the additiveand fuel products as a fuel.

The fuel may be used in any kind of power unit, including, but notlimited to, a boiler, a turbine, internal combustion engine, or anyother type of appropriate application.

Both the foregoing general description and the following detaileddescription are exemplary and explanatory only, and are not restrictiveof the invention as claimed. The accompanying drawings, which areincorporated herein by reference, and constitute a part of thespecification, illustrate certain embodiments of the invention and,together with the detailed description, serve to explain the principlesof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated by the data in the accompanying tables and graphs, anddisclosed in the accompanying claims, the present invention is a fueladditive for motor fuels for internal combustion engines, comprising:nitroparaffin, and a solubilizing agent. As embodied herein, thesolubilizing agent may be any of various esters, including withoutlimitation: ester oil, alcohol, amines and/or aromatic hydrocarbon. Theinvention comprises an improved fuel additive formulation, and method ofmaking and using the formulation.

The present inventors have developed a new method of creating a stablemixture of nitroparaffins in gasoline and/or diesel fuel, namely byintroduction of an ester oil and/or other solubilizing agent and/oraromatic hydrocarbon component and a mixing procedure of the presentinvention. The present inventors have discovered that low concentrationsof additives reduce emissions, provided the ester oil has been modifiedin accordance with the present invention, or another suitablesolubilizing agent is used. Specifically, the ester oil is modified toremove, or not to introduce, the tricresyl phosphate component ofcommercially available ester oils, and the solubilizing agent has atleast one chemically polar end and at least one chemically non-polarend. Toxicity has been reduced by eliminating, modifying, and/orreplacing components and by reducing the concentration of additive inthe fuel, while reducing emissions.

Emission reductions are achieved by the removal, introduction,modification, or reduction of various components. For example, tricresylphosphate has been substantially removed from, or not introduced into,commercially available ester oil; a solubilizing agent has beensubstituted for the ester oil; 2-nitropropane has been reduced orremoved from the prior known formulation; the concentration of ester oiland/or solubilizing agent, and nitromethane have been reduced relativeto certain prior known formulations; and/or the overall concentration ofadditive in the fuel has been reduced to a level lower than thattypically used in prior known inventions.

The present inventors have found that the solubility of nitromethane,which is normally highly explosive and dangerous, is reduced whenintroduced as a component of the fuel mixture (c. 170 mg/l), to theorder of the solubility of gasoline hydrocarbons (c. 120 mg/l), andsubstantially lower than the relatively high water solubility of a blendof 10% MTBE in gasoline (5000 mg/l). The present inventors have foundthat careful balancing of the formulation between the various componentsis necessary to make the product safely, while maintaining superioremission reduction capacity.

The present inventors have developed a number of improvements that theybelieve contribute to the beneficial effect of the invention onemissions.

First, the ester oil component of the present invention comprises esteroil that has been modified from its commercially available form. In thepresent invention, ester oil is present not for the purpose of uppercylinder lubrication in order to reduce friction as it was in priorknown formulations but, rather, to enhance the miscibility of thenitroparaffins in gasoline. Commercially available ester oils typicallyinclude various additive packages. The additives typically include avariety of substances that impart various characteristics to the esteroil, such as resistance to combustion, corrosion resistance, stability,and a wide variety of other properties. Prior inventors and theformulations known prior to the present invention taught that the esteroil should be used in the form in which it was commercially available,namely, including the additives found in commercially available esteroil products.

A number of these additives, however, are highly toxic and are knownenvironmental contaminants. In addition, some impart properties that arenot desired in a fuel formulation, such as flame retardancy. Thefunction of these flame retardants is to preserve the ester oil bypreventing it from burning. In this manner, the ester oil remainsavailable to lubricate the upper cylinder. Some of the prior inventors,including Michaels, specifically taught the benefits that flow fromretaining this property. Moreover, the ester oil is present in such alow concentration in the present invention (i.e., preferably about 1.8volume percent of the additive formulation, or 0.00142 volume percent ofthe fuel) that the flame retardant properties of commercially availableester oil would be expected by persons of ordinary skill in the art tohave a negligible effect, if any, on the performance of the presentinvention.

The present inventors, however, in contrast to each of the prior knownformulations, have modified the additive package of the ester oil,producing unexpected, beneficial properties. The present inventors,working with commercially available ester oil (Mobil Jet II Oil) haveremoved or eliminated one of the additive components—tricresylphosphate—from the ester oil. Although tricresyl phosphate is toxic, itis present in commercially available formulations of Mobil Jet II Oil.Contrary to the teachings of Michaels to employ commercially availableester oil, the present inventors have modified the ester oil of thepresent invention to be substantially free of this toxic component. Thepresent inventors believe that chemically removing the tricresylphosphate and/or no adding it has modified the ester oil in a mannerbeneficial to the present invention. It is within the knowledge of oneof ordinary skill in the art how to modify an ester oil to remove, ornot to introduce, tricresyl phosphate. In conjunction with the otherfeatures of the present invention, the present inventors have discoveredthat the performance and ability to lower emissions was improved by thepresent invention to an unexpected degree.

The ester oil in the additive, and the additive in the fuel, are presentin such low concentrations in the present invention that persons ofordinary skill in the art would have expected that removal of onecomponent of the ester oil would produce no effect on the performance ofthe fuel or its ability to reduce emissions, particularly in view of theteachings of Michaels. Yet, the present inventors have observedprecisely those benefits from the present invention. The presentinventors believe that the removal of the tricresyl phosphate componentof the ester oil may have affected the invention in any of severalpossible ways: by forming a new composition of matter, by modifying theester oil or one or more of its components in some manner; byemulsifying or suspending the nitroparaffins in the fuel; by some formof ionic reaction; by some form of methylation reaction; or by affectingthe solubility of one or more of the components of the presentinvention. The inventors are continuing their investigation.

Persons of ordinary skill in the art would not have expected thebenefits of the present invention, at the time the invention was made.Removal of the flame retardant involves a trade off. Presence of theflame retardant enables the ester oil to survive combustion and provideincreased upper cylinder lubrication. Prior inventors, such as Michaels,have attributed at least some measure of the improved performance oftheir additives to improved upper cylinder lubrication from the esteroil. On the other hand, the present inventors have discovered thatimproved upper cylinder lubrication is not as critical to the presentinvention as the benefits resulting from the removal of the flameretardant. Whereas Michaels focused on increasing horsepower and fuelefficiency, both of which were related to improving upper cylinderlubrication, the present inventors are attempting to reduce emissions,and in particular emissions on cold start-up. In this regard, removal ofthe tricresyl phosphate from the ester oil produces unexpected,beneficial results. In addition, a solubilizing agent may be substitutedfor the ester oil. The solubilizing agent will be described in greaterdetail in the following pages.

Second, 2-nitropropane is eliminated from certain embodiments of thepresent invention. Rather, 1-nitropropane is used in lieu of2-nitropropane in these embodiments of the present invention.2-nitropropane is toxic. Removal of 2-nitropropane and replacement withthe less toxic 1-nitropropane enhances safety by reducing potentialexposure to toxics. In contrast, prior known formulations, such asMichaels', used 2-nitropropane exclusively. Others simply failed todistinguish between 1-nitropropane and 2-nitropropane.

Third, the present inventors have preferably reduced the ratio of esteroil to nitroparaffin. This, in turn, reduces emissions from combustionof the ester oil. The ratio of ester oil to nitroparaffin has beenreduced to levels well below the levels employed in many prior knownformulations. Michaels teaches the use of ester oil at levels of 10 to90% of the additive formulation, in contrast to the preferred range ofless than about 10% and more preferrably less than about 2%, in thepresent invention. Michaels taught that higher concentrations of esteroil were necessary to provide upper cylinder lubrication and to make ahomogenous fuel. He recommends a maximum concentration of 25% ester oilto prevent potential engine fouling. The present inventors have producedbeneficial effects at concentrations far below the lower limits ofMichaels' range.

Fourth, toluene has been added in certain embodiments of the presentinvention to enhance engine combustion and improve emissions. Toluene isa component of gasoline. Toluene emulsifies and/or improves thesolubility of the nitroparaffins in gasoline, reducing the amount ofester oil required. This substitution permits the present inventors tosubstitute a lower emission ingredient (toluene) for a higher emissioningredient (ester oil). In the process, it allows for the properemulsion of the nitroparaffins into the additive and, ultimately, thefuel. The present inventors have found that toluene enhances andaugments the effect of the ester oil in the present invention to enhancethe solubility of nitroparaffins in gasoline.

Fifth, the present inventors preferably have limited the amount ofnitromethane in the formulation. Nitromethane is highly toxic as well asdangerous. It presents a substantial hazard of explosion and danger topersonal safety. Limiting the concentration of nitromethane reduces therisk and lowers the toxicity of the additive and, in turn, of the fuelin which it is used.

The toxic nature of the ingredients was not considered in earlierpatents. The present inventors have made several modifications to theformulation of the present invention to reduce the health risks posed bythe toxic components of the formulation. The inventors have alsomodified the formulation to reduce emission from engines using thepresent invention. The low concentration of additive package in thefuels of the present invention achieves these objectives. The higherconcentration employed in prior known formulations and disclosed inprior patents would result in higher emission of NOx, uncombustednitroparaffins, and total hydrocarbons and non-methane hydrocarbons.They would also tend to increase ozone formation. This would result fromboth the higher concentrations of ester oils and higher concentrationsof nitroparaffins, typically found in the prior known formulations. Atthe relatively high concentrations of ester oils and nitromethanedisclosed in prior known formulations, the fuel would be substantiallymore toxic and pose greater risks to ground water. Emissions would beincreased in general, specifically of toxic materials. The presentinventors have found that only at low concentrations of ester oil andnitromethane can emissions be reduced.

Sixth, the present inventors preferably have systematized the productionof the formulation of the present invention. Prior known additives havebeen prepared in small quantities, on a batch basis, often without thebenefit of production standards, and little to no attention toproduction quality control.

In contrast to the process of the present invention, Michaels statesthat there is no general rule as to the amount of ester oil orsolubilizing agent needed because gasoline varies by type and varieswidely even from the same refinery, depending on multiple variables suchas: the available crudes, refinery operations, and the time of year.Michaels' approach requires continuous monitoring to ensure that properhomogeneous fuels are being blended. Michaels' approach for determiningthe proper blend of ester oil, nitroparaffin, and gasoline requires thatnitroparaffin be added to the gasoline, then that sufficient ester oilbe added to the gasoline in increments. Specifically, Michaels requiresthe addition of a small amount of ester oil followed by mixing, followedby the addition of added amounts of ester oil, repeating the processuntil a homogeneous blend is obtained in the fuel. Michaels does notdisclose the use of a solubilizing agent as disclosed and claimed by thepresent inventors.

Thus, Michaels' fuels must be mixed in a batch process. In contrast, thepresent invention is not so limited. The present invention can be addedto any fuel. Moreover it can be added in standard amounts, as continuousadjustment is not required in order to make a homogeneous fuel. Thus,the present invention allows the additive to be made and blended in abatch or continuous process that can readily be standardized for aproduction-scale operation.

The present inventors anticipate that a preferred production scaleprocess would involve the following steps:

-   -   1. In a clean stainless steel vessel;    -   2. Per 55 gallons of additive, add 1 gallon of modified ester        oil (from which substantially all of the tricresyl phosphate has        been removed), or a solubilizing agent;    -   3. Add 5 gallons of toluene;    -   4. Let ingredients stand 10 minutes at ambient temperature, do        not mix;    -   5. Add 10 gallons of nitromethane;    -   6. Add 10 gallons of nitroethane;    -   7. Add 29 gallons of 1-nitropropane;    -   8. Mix by aeration through a narrow tube at low pressure, at        ambient temperature, venting the mixing vessel to ambient        atmospheric pressure;    -   9. Recover nitromethane evaporate through the use of a condenser        in the vent;    -   10. Store the additive formulation until ready for use;    -   11. Mix the additive with motor fuel (gasoline, gasoline and        MTBE, gasoline and ethanol, and/or gasoline and ethanol and        MTBE), preferably at a concentration of 0.1 oz. per gallon of        fuel (0.07812%), in gasolines, and preferably at a concentration        of 0.2 oz. per gallon of fuel (0.15624%) in diesel fuel.        The inventors believe that the unexpected results of the present        invention are attributable, at least in part, to the processing        and order of addition of the ingredients, as set forth above. In        a preferred embodiment of the present invention, the mixing step        preferably is accomplished by bubbling air at low pressure        (10-psig) through a narrow diameter tube (¼″-⅜″ in diameter),        for 10-15 minutes.

It will be apparent to persons of ordinary skill in the art thatmodifications and variations may be made in the manner of combining theingredients to produce the additive formulation of the presentinvention. For example, the mixing vessel could be epoxy-lined steel orany other suitable material. To the extent that reactive intermediariesor reaction products are formed, the selection of material for themixing vessel may be guided by the desire not to cause any furtherinteraction between the ingredients or, alternatively, to facilitate orcatalyze any reactions that may occur. Moreover, the process may be runon a batch or continuous basis. On a continuous basis, the residencetimes may be adjusted to achieve the above hold times. Moreover, thetoluene and ester oil may be mixed separately, either on a batch orcontinuous basis. Similarly, the nitromethane and nitroethaneingredients may be combined, in order to reduce the material-handlingdifficulties of nitromethane. Thus, it is intended that the inventioninclude the variations and permutations of the method of combining theingredients, provided they come within the scope of the appended claimsand their equivalents.

The method of preparing the formulation of the present inventionincludes steps to ensure that the components are properly mixed, whilereducing off-gassing which would otherwise occur during processing. Forexample, the present inventors use a simple condenser to collect thenitromethane released during processing.

Seventh, the present inventors anticipate that, in contrast to the“homogeneous” “blend” disclosed by Michaels, the present formulation maypreferably comprise one or more reaction products, formed by theinteraction of various of the components of the formulation.Alternatively, modification of the ester oil may have changed thecomposition of the ester oil component. As a further alternative, thepresent inventors may emulsify or suspend the nitroparaffins, ester oil,and/or toluene, in the fuel. Ionic or methylation reactions may haveoccurred, or the combination of the ingredients may affect thesolubility of one or more components in others. The present inventorsare continuing their evaluations, attempting to discover the precisenature of these potential interactions in the present invention.

Finally, the present invention achieves improved performance, as well asreduced emissions at lower concentrations of additive than prior knownformulations. Wholly apart from the existence of any reaction products,reactive intermediaries, or interaction between the components of theinvention, the present invention differs from prior known formulationsin various ways. Whereas Michaels combined nitroparaffins and ester oilsin a ratio of from 10 to 90% to 90 to 10%, the present inventioncombines them in proportions outside those ranges, namely, less thanabout 20%, and preferably less that 10%, ester oil to nitroparaffin.More specifically, the present invention would limit the ester oil tonitroparaffin ratio to less than about 10%. In another preferredembodiment of the present invention, the ratio of ester oil tonitroparaffin would be less than about 2%, namely, about 1.8% by volume.

The amount of additive used per gallon of fuel in the present inventionis well below the amounts taught by Michaels. Whereas Michaels includesadditive at levels of 5% to 95% of the amount of gasoline, the additiveof the present invention is typically used in amounts less than about20%. More specifically, the amount of additive is generally less than10%, or 5%. In a preferred embodiment of the present invention, theamount of additive preferably is maintained below about 0.1%, namelyabout 0.08% (or 0.1 of an ounce of additive per gallon of fuel).

The present invention comprises a fuel additive formulation and a methodof making and using same. The fuel additive formulation of the presentinvention preferably comprises: 1-nitropropane, nitroethane,nitromethane, toluene, and ester oil and/or a solubilizing agent Whenused as a motor fuel for automobiles and other internal combustionengines, the present invention preferably comprises from 0.01% to lessthan about 5% additive by volume, in gasoline.

In these ranges, the amount of nitroparaffin in Michaels' fuels is wellabove the range of the present invention. Whereas Michaels includesnitroparaffin in amounts ranging from 0.5% to 85.5%, the amount ofnitroparaffin in fuels of the present invention typically ranges from0.064% to 7.6% by volume, and preferably below 0.5% by volume.

The present invention comprises a continuous range of combinations ofester oil and/or toluene, on one hand, and nitroparaffin, on the other.The present inventors believe that the function of the ester oil andtoluene in the present invention is to allow the nitroparaffins to reactwith, emulsify with, or become soluble in, gasoline. Either tolueneand/or ester oil may be used. Preferably both are used. The followingtable illustrates, without limitation, some of the ranges oftoluene/ester to nitroparaffin of the present invention:

TABLE 6 Ratio of Toluene/Ester Oil to Nitroparaffin in the Additive ofthe Present Invention Toluene and/or Ester Oil (Volume percent)Nitroparaffin 0 ≦ x ≦ c. 20% c. 80 ≦ x ≦ c. 100% 0 ≦ x ≦ c. 15% c. 85 ≦x ≦ c. 100% 0 ≦ x ≦ c. 10% c. 90 ≦ x ≦ c. 100% 0 ≦ x ≦ c. 5% c. 95 ≦ x ≦c. 100% c. 0.1 ≦ x ≦ c. 10% c. 90 ≦ x ≦ c. 99.9% c. 0.1 ≦ x ≦ c. 5% c.95 ≦ x ≦ c. 99.9% c. 0.5 ≦ x ≦ c. 3.5% c. 96.5 ≦ x ≦ c. 99.5% c. 0.5 ≦ x≦ c. 2.5% c. 97.5 ≦ x ≦ c. 99.5% c. 1.0 ≦ x ≦ c. 2.5% c. 97.5 ≦ x ≦ c.99.0%

The present invention comprises one or more nitroparaffins. As embodiedherein, the nitroparaffins of the present invention comprise:nitromethane, nitroethane, and/or nitropropane. Each may be present incombination with, or to the exclusion of, the others. For example, eachof nitromethane, nitroethane, and nitropropane may comprise from 0% to100% of the nitroparaffin component of the invention identified in Table6. In a preferred embodiment of the present invention, nitromethane isthe preferred nitroparaffin. Preferably, nitromethane is present as 20%to 40% of the nitroparaffin fraction of the additive, and morepreferably, as 20% of the additive formulation. Table 7 illustrates,again without limitation, some of the ranges of nitroparaffins of thepresent invention:

TABLE 7 Relative Proportions of Various Nitroparaffins in theNitroparaffin Component of the Additive of the Present InventionNitromethane Nitroethane Nitropropane 0 ≦ x ≦ 100% 0 ≦ x ≦ 100% 0 ≦ x ≦100% c. 10 ≦ x ≦ c. 50% c. 0 ≦ x ≦ c. 90% c. 0 ≦ x ≦ c. 90% to to c. 0 ≦x ≦ c. 50% c. 0 ≦ x ≦ c. 50% c. 20 ≦ x ≦ c. 40% c. 0 ≦ x ≦ c. 80% c. 0 ≦x ≦ c. 80% to to c. 0 ≦ x ≦ c. 60% c. 0 ≦ x ≦ c. 60% c. 20 c. 0 ≦ x ≦ c.80% c. 0 ≦ x ≦ c. 80% c. 20 c. 20 c. 60 c. 10 c. 0 ≦ x ≦ c. 90% c. 0 ≦ x≦ c. 90% c. 10 c. 10 c. 80

Although the present inventors believe that the influence ofnitromethane is more important than other nitroparaffins in the effectof the present invention, nitromethane is relatively more dangerous, interms of material handling, environmental, and public health risk, thannitroethane and/or nitropropane. Nitromethane is more toxic. Moreover,nitromethane poses a greater explosion hazard, necessitating carefulmaterial handling steps that are well known to persons of ordinary skillin the art of handling such volatile compounds. It is imperative inorder to practice the invention that generally accepted materialhandling procedures be followed in order to reduce the risk of bodilyharm and/or explosion hazard.

Based upon the above continuous ranges of composition, certain ranges ofthe principal components of the present invention are illustrated,without limitation, in Table 8:

TABLE 8 Components of the Present Invention Volume Percent Component ofAdditive Volume Percent of 1-nitropropane 0 ≦ x ≦ 80% 0 ≦ x ≦ 0.0624Nitroethane 0 ≦ x ≦ 80% 0 ≦ x ≦ 0.0624 Nitromethane 0 ≦ x ≦ 80% 0 ≦ x ≦0.0624 Toluene 0 ≦ x ≦ 20% 0 ≦ x ≦ 0.0156 Ester Oil 0 ≦ x ≦ 20% 0 ≦ x ≦0.0156

The relative amounts of the various nitroparaffins are adjusted tocompliment one another, as are the relative amounts of toluene and esteroil. The relative amount of nitroparaffin, on one hand, and ester oiland toluene on the other, are also adjusted to compliment one another.As will be seen from Table 8, the proportions of the components of thepresent invention are below the ranges of those components in priorknown formulations.

In one preferred embodiment of the present invention, the presentinvention comprises:

TABLE 9 Formulation of a Preferred Embodiment of the Present InventionComponent Parts Proportion of Fuel 1-nitropropane 29 0.026 Nitroethane10 0.009 Nitromethane 10 0.009 Toluene 5 0.00455 Ester Oil 1 0.00091

The ester oil of the present invention includes little to no flameretardant. The present inventors believe that this modification enablesthe present invention to reduce emissions on cold start up. This resultwas surprising, particularly given the long-standing and widespread useof various commercial, additive-containing ester oils. The presentinventors have found, however, that this modification results inimproved cold start up emissions to a degree that more than compensatesfor any negative effect in terms of reduced upper cylinder lubricationthrough combustion and loss of the ester oil.

The present inventors have conducted a series of experiments to test theperformance of the present invention relative to various knownformulations. These formulations are identified in the followingexamples.

EXAMPLE 1

Indolene was used as a standard reference fuel. The Indolene waspurchased from Philips Chemical Company: UTG 96 (OBPU9601).

EXAMPLE 2

Indolene was blended with EChem. The Indolene was the standard referencefuel, of Example 1, above. The EChem formulation used in testing thepresent invention was obtained from Don Young. The EChem formulation wasprepared by: combining 1 gallon of commercially available Mobil Jet IIOil and 5 gallons of toluene in an epoxy-lined steel drum that had beenflushed; allowing the toluene/ester oil mixture to stand for 10 minutes;adding 10 gallons of nitromethane; adding 10 gallons of nitroethane;adding 29 gallons of 1-nitropropane; and aerating the ingredientsthrough a narrow tube at low pressure, and ambient temperature; toproduce the additive. The EChem additive was added to Indolene at a rateof 0.1 oz. per gallon of fuel.

EXAMPLE 3

The MAZ 100 formulation of the present invention was prepared asfollows:

-   -   1. An epoxy-lined 55 gallon drum was flushed;    -   2. 1 gallon of ester oil (modified Mobil Jet II Oil, without the        tricresyl phosphate additive) was added;    -   3. 5 gallons of toluene were added;    -   4. The ester oil and toluene were allowed to stand 10 minutes at        ambient temperature and pressure;    -   5. 10 gallons of nitromethane were added to the mixture;    -   6. 10 gallons of nitroethane were added to the mixture;    -   7. 29 gallons of 1-nitropropane were added to the mixture;    -   8. The components were mixed by gentle aeration, through a        narrow tube at low pressure, at ambient temperature, venting the        mixing vessel to ambient atmospheric pressure;    -   9. The MAZ 100 additive formulation was then stored until needed        for testing;    -   10. The additive was mixed with a reference motor fuel        (indolene), at a concentration of 0.1 oz. of MAZ 100 additive        per gallon of Indolene (0.07812%).

EXAMPLE 4

Indolene was procured as noted above in Example 1, from PhillipsChemical Company. MBE was added at 11%.

EXAMPLE 5

RFG II was secured from Phillips Chemical Company. The RFG formulationused in the testing was California P-II CERT Fuel (0CPCP201).

The present inventors have run a number of comparisons of the presentformulation relative to other fuels. The results are tabulated below, inTables 10 through 13.

TABLE 10 MAZ 100 Formulation Results of Emission Testing (Grams emittedper mile) Indolene EChem 1 MAZ 100 Carbon Monoxide 2.090 2.142 2.056 NOx0.562 0.565 0.546 Total Hydrocarbons 0.311 0.310 0.256 Non-Methane 0.2840.282 0.229 Hydrocarbons Ozone 0.965 1.016 0.775

TABLE 11 MAZ 100 Formulation vs. EChem 1 Formulation Improvement overIndolene EChem 1 MAZ 100 Difference Carbon Monoxide −2%  2%  4% NOx −1% 3%  4% Total Hydrocarbons  0 18% 18% Non-Methane  1% 19% 18%Hydrocarbons Ozone −5% 20% 25%

MAZ 100 was tested in a 1992 Plymouth Voyager using a chassisdynamometer. The tests were conducted at the University of California,Riverside, College of Engineering Center for Environmental Research andTechnology (CE-CERT) facility, following the Federal Test Protocol(FTP). A total of four fuels were tested to evaluate the performance ofthe additive in gasoline. The four fuels tested were: (Fuel 1) Indolene;(Fuel 2) Indolene with 0.1 percent by volume MAZ 100; (Fuel 3) Indolenewith 11 percent by volume MTBE; and (Fuel 4) Phase II Federal RFG.

The MAZ 100 formulation of the present invention was prepared by MagnumEnvironmental Technologies, Inc., staff prior to the initiation oftesting. The staff acquired nitromethane, nitroethane, and1-nitropropane from Angus Chemicals, and Synthetic Ester Oil (TCP-freeMobil Jet 2) from Mobil Chemical Company and they acquired toluene fromVan Waters & Rogers Chemical Distributors. The staff mixed 10 partsnitromethane, 10 parts nitroethane, 29 parts 1-nitropropane, 5 partstoluene, and 1 part ester oil in the manner described above to form theMAZ 100 additive. This material was provided to CE-CERT and used toconduct the tests at CE-CERT.

CE-CERT acquired certified Indolene (UTG 96) and certified Phase IICalifornia RFG from the Phillips Chemical Company. Commercial Grade MTBE(95% MTBE) was obtained by CE-CERT from ARCO. Magnum EnvironmentalTechnologies supplied the “MAZ 100” additive. CE-CERT staff prepared twoof the four test fuels (Fuel 2 and Fuel 3 above) by blending either the“MAZ 100” additive or MTBE with the appropriate certified gasoline priorto conducting the tests. CE-CERT staff prepared Fuel 2 by placing 0.1percent by volume of the MAZ 100 into Indolene and mixing the resultingtest fuel CE-CERT staff prepared Fuel 3 by placing 11 percent by volumeof MTBE into Indolene and mixing the resulting test fuel. No mixing wasnecessary for Fuel 1 and Fuel 4.

Each fuel was tested in the 1992 Voyager following the Federal TestProtocol. The test was repeated three times for each fuel. During eachtest run, exhaust samples were collected in Tedlar bags and the contentsof the each bag were analyzed for the presence of: (1) carbon monoxide(CO), (2) nitrogen oxides (NO_(x)); (3) non-methane hydrocarbons; and(4) volatile organic compounds (VOCs) that are precursors to ozoneformation to enable prediction of the ozone formation potential for eachtest fuel.

The Federal Test Protocol consists of three phases: Phase 1 correspondsto cold starts; Phase 2 corresponds to the transient phase in which theengine speed is varied; and Phase 3 corresponds to the hot start phase.Exhaust samples were collected during each of the three phases of theFTP in separate bags during each test run. The first phase,corresponding to cold starts was collected in Bag 1 for each test run.The exhaust samples corresponding to the transient phase were collectedin Bag 2 for each test run. The exhaust samples corresponding to the hotstart phase were collected in Bag 3 for each test run.

All four test fuels were tested in the same 1992 Plymouth Voyager and asufficient volume of test fuel was rinsed through the vehicle's fuelsystem and drained to remove traces of the previous test fuel to assurethat the results represent the current test fuel. Each test fuel usedwas also subjected to chemical analysis to verify the hydrocarbon andother compounds present in the test fuel.

The measured CO, NO_(x), non-methane hydrocarbons, and ozone formationpotential for each test fuel were recorded and compared for all fourfuels. The present inventors have run a number of comparisons of thepresent formulation relative to other fuels. The results are tabulatedbelow, in Tables 12 and 13. The present invention is represented by theinformation for “MAZ 100”:

TABLE 12 MAZ 100 Formulation Results of Emissions Testing (grams/mile)Indolene Indolene Plus 11% Plus Indolene MTBE RFG II MAZ 100 CarbonMonoxide 2.090 2.488 2.121 2.056 NOx 0.562 0.593 0.527 0.546 TotalHydrocarbons 0.311 0.237 0.287 0.256 Non-Methane 0.284 0.213 0.255 0.229Hydrocarbons Ozone 0.966 N/A* 0.807 0.775 *Results were not available.

Based upon the above information, the following percentage improvementsin emissions were observed:

TABLE 13 MAZ 100 Formulation Emissions Improvement Relative to IndoleneIndolene Plus 11% Indolene Plus MTBE RFG II MAZ 100 Carbon Monoxide−19%  −1%  2% NOx −5%  6%  3% Total Hydrocarbons 24%  8% 18% Non-Methane25% 10% 19% Hydrocarbons Ozone N/A* 16% 20% *Results were not available.

For the test vehicle used, the present invention produced resultssuperior to the reference fuel, and MTBE, on numerous criteria. Thepresent inventors believe that the results of the present invention maynot be reproduced using a vehicle made after approximately 1994, as suchvehicles are equipped with oxygen sensors and advanced computer enginecontrols that can rapidly adjust fuel to oxygen ratios and timingminimizing the beneficial effects of the additive on emissions.Nonetheless, the present inventors believe that the beneficial effectsof the present invention in the 1992 vehicle are due to themodifications and variations of the invention relative to prior knownformulations that failed to achieve the beneficial effects of thepresent invention.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the construction andconfiguration of the present invention without departing from the scopeor spirit of the invention. Thus, it is intended that the presentinvention cover the modifications and variations of the inventionprovided they come within the scope of the appended claims and theirequivalents. For example, the additive formulation may be preparedcomprising a nitroparaffin and a solubilizing agent.

As illustrated by the data in the accompanying tables and graphs, anddisclosed in the accompanying claims, a preferred embodiment of thepresent invention is a fuel additive for motor fuels for internalcombustion engines, comprising nitroparaffin and a solubilizing agent,wherein the solubilizing agent comprises at least one chemically polarend and at least one chemically non-polar end. The chemically polar endsmay comprise ether groups, or any other suitable chemically polar group.The chemically non-polar ends may comprise hydrocarbon groups, or anyother suitable chemically non-polar group.

A preferred embodiment of the present invention is a fuel additive formotor fuels for internal combustion engines, comprising nitroparaffinand an ester compound, wherein the ester compound comprises at least onechemically polar end and at least one chemically non-polar end. Thechemically polar ends may comprise ether groups, or any other suitablechemically polar group. The chemically non-polar ends may comprisehydrocarbon groups, or any other suitable chemically non-polar group.

A preferred embodiment of the present invention is a fuel additive formotor fuels for internal combustion engines, comprising nitroparaffinand a simple ester compound, wherein the simple ester compound comprisesat least one chemically polar end and at least one chemically non-polarend. The chemically polar ends may comprise ether groups, or any othersuitable chemically polar group. The chemically non-polar ends maycomprise hydrocarbon groups, or any other suitable chemically non-polargroup. The simple ester compound may be prepared by reacting etheralcohols and monobasic acids, or any other suitable reactants that wouldgive rise to a simple ester compound. The simple ester compound may be asimple ether alcohol ester.

A preferred embodiment of the present invention is a fuel additive formotor fuels for internal combustion engines, comprising nitroparaffinand an amino alkane compound, wherein the amino alkane compoundcomprises at least one chemically polar end and at least one chemicallynon-polar end. The chemically polar ends may comprise amino groups, orany other suitable chemically polar group. The chemically non-polar endsmay comprise hydrocarbon groups, or any other suitable chemicallynon-polar group. The amino alkane compound may have the followingformula:

wherein R₁ and R₂ are either hydrogen, alkyl (methyl, ethyl, propyl, orany other compatable group) or aryl, and n can vary from 1 to 8. Themain hydrocarbon chain may also be branched. The compound may alsocontain two or more amino groups having alkyl or aryl substituents.Compounds containing various combinations of ether, ester and aminogroups are also expected to be useful as solubilizing agents fornitroalkanes in gasoline.

In a preferred embodiment of the present invention, the amino alkanecompounds may further comprise:

Where n=6 would be (1-methylaminoheptane);

1-Dimethylamino-3-hexanoyloxypropane;

1-(N-Ethyl-N-methyl)amino-2 proyloxyethane; and

1-(N-Ethyl-N-methyl)amino-2-oxy-pentanoyloxyethyl ether.

The simple ether alcohol esters may be synthesized by several routesknown by persons of ordinary skill in the art. The acid chloride routewas chosen to synthesize the bulk of these esters since the synthesis isrelatively fast, and is easy to accomplish in excellent yields. Thisroute would not be the choice for commercial production since thestarting acid chlorides are considerably more expensive than thecorresponding acids. Also, the acid chloride synthesis involves the useof ether, a volatile and explosive compound.

The preferred commercial route to obtain the identical esters would beby the direct reaction of the alcohol with the acid, over an acid resincatalyst. This route involves the removal of water during reaction,several filtrations, and a distillation step, common methods inindustrial chemistry.

The following section describes six additional examples for preparingthese esters using two alcohols and two acid chlorides, in the presenceof an amine. Example 12 describes the synthesis of one of these estersusing the direct reaction route of adding the acid to the alcohol, inthe presence of an acid resin catalyst. In Example 12, the acid catalystis recovered and is reusable, and so is the n-octane, which is recoveredby distillation. Thus Example 12 would be the more economical and saferoute to obtain these esters.

EXAMPLE 6 Preparation of Diethylene Glycol Ethyl Ether (carbitol™) Esterof n-Octanoic Acid (C8)

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was than partially immersed in a cold water bath. The additionfunnel was then charged with 163 grams of n-octanoyl chloride. The acidchloride was added to the flask while stirring. The entire mixture wasmaintained in the water bath, while stirring, for two hours, to allowthe exothermic reaction to subside. After the exotherm subsided, theflask was kept in cold water for an additional hour. The reactionmixture was then filtered to remove the amine hydrochloride solid. Thefiltrate was then vacuum stripped from a heated water bath atapproximately 200 mm pressure. The residue was then extracted once witha 2% aqueous sodium sulfate and was dried over solid anhydrous sodiumsulfate and filtered to give the final product.

EXAMPLE 7 Preparation of Diethylene Glycol Ethyl Ether Ester ofn-Hexanoic Acid (C6)

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was then partially immersed in a cold water bath. The additionfunnel was then charged with 163 grams of n-hexanoyl chloride. The acidchloride was added to the flask while stirring. The entire mixture wasmaintained in the water bath, while stirring, for two hours, to allowthe exothermic reaction to subside. After the exotherm subsided, theflask was kept in cold water for an additional hour.

The reaction mixture was then filtered to remove the amionehydrochloride solid. The filtrate was then vacuum stripped from a heatedwater bath at approximately 200 mm pressure. The residue was thenextracted once with a 2% aqueous sodium sulfate and was dried over solidanhydrous sodium sulfate and filtered to give the final product.

EXAMPLE 8 Preparation of Ethylene Glycol Ethyl Ether (cellosolve™) Esterof n-Hexanoic Acid

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was then partially immersed in a cold water bath. The additionfunnel was then charged with 163 grams of n-hexanoyl chloride. The acidchloride was added to the flask while stirring. The entire mixture wasmaintained in the water bath, while stirring, for two hours, to allowthe exothermic reaction to subside. After the exotherm subsided, theflask was kept in cold water for an additional hour.

The reaction mixture was then filtered to remove the amionehydrochloride solid. The filtrate was then vacuum stripped from a heatedwater bath at approximately 200 mm pressure. The residue was thenextracted once with a 2% aqueous sodium sulfate and was dried over solidanhydrous sodium sulfate and filtered to give the final product.

EXAMPLE 9 Preparation of Ethoxy Ethyl Ether Ester of n-Octanoic Acid

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was then partially immersed in a cold water bath. The additionfunnel was then charged with 163 grams of n-hexanoyl chloride. The acidchloride was added to the flask while stirring. The entire mixture wasmaintained in the water bath, while stirring, for two hours, to allowthe exothermic reaction to subside. After the exotherm subsided, theflask was kept in cold water for an additional hour.

The reaction mixture was then filtered to remove the amionehydrochloride solid. The filtrate was then vacuum stripped from a heatedwater bath at approximately 200 mm pressure. The residue was thenextracted once with a 2% aqueous sodium sulfate and was dried over solidanhydrous sodium sulfate and filtered to give the final product.

EXAMPLE 10 Preparation of Ethoxy Ether Ester with a mixture ofn-Octanoic Acid and n-Hexanoic Acids

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was then partially immersed in a cold water bath. The additionfunnel was then charged with 81.5 grams of n-octanoyl chloride and 81.5grams of n-hexanoyl chloride. The acid chloride was added to the flaskwhile stirring, for two hours, to allow the exothermic reaction tosubside. After the exotherm subsided, the flask was kept in cold waterfor an additional hour.

The reaction mixture was then filtered to remove the amionehydrochloride solid. The filtrate was then vacuum stripped from a heatedwater bath at approximately 200 mm pressure. The residue was thenextracted once with a 2% aqueous sodium sulfate and was dried over solidanhydrous sodium sulfate and filtered to give the final product.

EXAMPLE 11 Preparation of Diethylene Glycol Ethyl Ether Ester with amixture of n-Octanoic Acid and n-Haxanoic Acids

A 3 liter flask equipped with a magnetic stirrer, thermometer andaddition funnel, was charged with 147 grams of diethylene glycol ethylether, 111 grams of triethyl amine and 200 ml of diethyl ether. Theflask was then partially immersed in a cold water bath. The additionfunnel was then charged with 81.5 grams of n-octanoyl chloride and 81.5grams of n-hexanoyl chloride. The acid chloride was added to the flaskwhile stirring. The entire mixture was maintained in the water bath,while stirring, for two hours, to allow the exothermic reaction tosubside. After the exotherm subsided, the flask was kept in cold waterfor an additional hour.

The reaction mixture was then filtered to remove the amionehydrochloride solid. The filtrate was then vacuum stripped from a heatedwater bath at approximately 200 mm pressure. The residue was thenextracted once with a 2% aqueous sodium sulfate and was dried over solidanhydrous sodium sulfate and filtered to give the final product.

EXAMPLE 12 Preparation of Diethylene Glycol Ethyl Ether Ester ofn-Octanoic Acid by Direct Esterefication

A 5 liter reaction flask equipped with a mechanical stirrer,thermometer, addition funnel and a Dean-Stark distillation adapter wascharged with 1600 ml of diethylene glycol monoethyl ether, 1260 ml ofoctanoic acid, 600 ml of n-octane and 79.6 grams of commercial Amberlistcatalyst resin (polystyrene sulfonic acid).

The reaction mixture was refluxed to remove 1366 ml of water from thereaction, over 1.5 hours. The flask was then cooled to room temperaturein a water bath, and the reaction product was then filtered to removethe catalyst resin. The reaction product was then washed twice with coldwater once with 0.5 molar sodium hydroxide, then twice again with coldwater. The material was then vacuum stripped at 125 mm pressure and 125C.

The purity of the final product was determined by measuring theasponification number (by titration). Saponification number for theproduct was 221 mg KOH/grams, versus a theoretical of 216 mg KOH/grams.

The miscibility and solubilizing effects were determined experimentallyby simple mixing experiments. These experiments involved bothcommercially purchased gasoline and Indolene, a synthetic “standard”used in the industry to simulate gasolines, and by mixing them withnitroparaffins, using the above mentioned solubilizing agents. Thesolubility experiments were set up in the following fashion.

Each experiment used the same size of test tube (13*100 mm). To eachtest tube, 5 cc of either gasoline or indolene were added. The gasolinewas purchased from Texaco, lowest grade, no lead. Indolene was used asreceived from Magnum Environmental Technologies. The Mobil Jet II Oilwas also used as received from Magnum Environmental Technologies.

To the gasoline or Indolene containing test tubes, 1 cc of nitromethaneand either 0.2 cc toluene (Tables 14 and 15), or no toluene (Tables 16and 17) were added. Both the nitromethane and toluene were as receivedfrom Aldrich Chemical. After these additions were made, each test tubewas inverted three times to insure proper mixing.

After mixing, each test tube exhibited two phases of liquid, indicatingnon-solubility.

A specific solubilizing agent was added, by drops, to each test tube.After each drop of solubilizing agent, the test tube was inverted threetimes, and allowed to stand and come to equilibrium for fifteen minutes.The solubilizing agent additions were continued until the phaseseparation disappeared, thus a complete solution occurred. Looking atthe results of Table 14, therefore, it means that it required 21 dropsof PPL solubilizing agent 272-60 to solubilize the mixture, 26 drops ofPPL solubilizing agent 305-35 and 39 drops of the Mobil Jet II Oil.

TABLE 14 SOLUBILITY EXPERIMENTS GASOLINE Gasoline Toluene NitromethaneExample # PPL# Acid Alcohol cc cc cc # Drops* 1 272-60 C8 carbitol 5 0.21 21 2 305-18 C6 carbitol 5 0.2 1 22 3 305-17 C6 cellosolve 5 0.2 1 21 4305-19 C8 cellosolve 5 0.2 1 23 5 305-24 Mix C6-C8 cellosolve 5 0.2 1 206 305-20 Mix C6-C8 carbitol 5 0.2 1 20 7 305-35 C8 carbitol 5 0.2 1 26Mobil Jet Oil — — 5 0.2 1 39

TABLE 15 SOLUBILITY EXPERIMENTS INDOLENE Gasoline Toluene NitromethaneExample # PPL# Acid Alcohol cc cc cc # Drops* 1 272-60 C8 carbitol 5 0.21 22 2 305-18 C6 carbitol 5 0.2 1 21 3 305-17 C6 cellosolve 5 0.2 1 20 4305-19 C8 cellosolve 5 0.2 1 22 5 305-24 Mix C6-C8 cellosolve 5 0.2 1 256 305-20 Mix C6-C8 carbitol 5 0.2 1 19 7 305-35 C8 carbitol 5 0.2 1 25Mobil Jet Oil — — 5 0.2 1 36

TABLE 16 SOLUBILITY EXPERIMENTS GASOLINE Gasoline Toluene NitromethaneExample # PPL# Acid Alcohol cc cc cc # Drops* 1 272-60 C8 carbitol 5 0 114 2 305-18 C6 carbitol 5 0 1 14 3 305-17 C6 cellosolve 5 0 1 15 4305-19 C8 cellosolve 5 0 1 14 5 305-24 Mix C6-C8 cellosolve 5 0 1 14 6305-20 Mix C6-C8 carbitol 5 0 1 14 7 305-35 C8 carbitol 5 0 1 14 MobilJet Oil — — 5 0 1 18

TABLE 17 SOLUBILITY EXPERIMENTS INDOLENE Gasoline Toluene NitromethaneExample # PPL# Acid Alcohol cc cc cc # Drops* 1 272-60 C8 carbitol 5 0 111 2 305-18 C6 carbitol 5 0 1 10 3 305-17 C6 cellosolve 5 0 1 11 4305-19 C8 cellosolve 5 0 1 11 5 305-24 Mix C6-C8 cellosolve 5 0 1 10 6305-20 Mix C6-C8 carbitol 5 0 1 11 7 305-35 C8 carbitol 5 0 1 11 MobilJet Oil — — 5 0 1 16

The present inventors have developed a new method of creating a stablemixture of nitroparaffins in gasoline and/or diesel fuel, namely byintroduction of a solubilizing agent, wherein the solubilizing agentcomprises at least one chemically polar end and at least one chemicallynon-polar end, and a mixing procedure of the present invention. Thepresent inventors have discovered that low concentrations of fueladditives reduce emissions. Toxicity has been reduced by eliminating,modifying and/or replacing components and by reducing the concentrationof additive in the fuel, while reducing emissions.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the construction andconfiguration of the present invention without departing from the scopeor spirit of the invention. Thus, it is intended that the presentinvention cover the modifications and variations of the inventionprovided they come within the scope of the appended claims and theirequivalents.

1. An additive formulation for a fuel comprising: a nitroparaffin; asolubilizing agent comprising relatively polar and relatively non-polarends comprising an ester compound, a simple ester compound, an esteralcohol, a simple ester alcohol, an ester ether alcohol, a simple esterether alcohol, amino alkane compound, and an ester amine; and anaromatic hydrocarbon; said fuel resulting in reduced emissions relativeto a fuel not containing said additive.
 2. The formulation of claim 1,wherein said solubilizing agent comprises at least one chemicallyrelatively polar and at least one chemically relatively non-polar end.3. The formulation of claim 1, wherein said solubilizing agentcomprises: an ester, ester alcohol, simple ester alcohol, ester etheralcohol, simple ester ether alcohol, amino alkane or ester amine.
 4. Theformulation of claim 1, wherein said nitroparaffin comprises:1-nitropropane, 2-nitropropane, nitroethane, nitromethane, or a mixturethereof.
 5. The formulation of claim 1, wherein said aromatichydrocarbon comprises an aliphatic derivative of benzene.
 6. Theformulation of claim 1, wherein said aromatic hydrocarbon comprises:benzene, ethyl benzene, xylene, or toluene.
 7. An additive formulationfor a fuel comprising: a first component, comprising about 0 to 99volume percent of: 1-nitropropane, 2-nitropropane, nitroethane,nitromethane, or a mixture thereof; a second component, comprisingsubstantially the balance of the additive formulation, of: esteralcohol, simple ester alcohol, ester ether alcohol, ester amine, or amixture thereof; and an aromatic hydrocarbon; the additive formulationfor reducing one or more emissions selected from the group consistingof: total hydrocarbons, non-methane hydrocarbons, carbon monoxide,NO_(x), and ozone precursors.
 8. The formulation of claim 7, whereinsaid first component comprises: 20 to 40 volume percent nitromethane,and 60 to 80 volume percent of: 1-nitropropane, 2-nitropropane,nitroethane, or a mixture thereof.
 9. The formulation of claim 7,further comprising less than 20 volume percent of an aromatichydrocarbon and less than 10 volume percent of said second component.10. The formulation or fuel of claim 7, wherein said formulation isadapted for use in a power unit comprising: a boiler, turbine, orinternal combustion engine.
 11. The formulation or fuel of claim 10,wherein said internal combustion engine comprises: a gasoline engine ora diesel engine.
 12. The formulation of claim 1, wherein said reducedemissions comprise: carbon monoxide, NO_(x), total hydrocarbon,non-methane hydrocarbon, ozone precursors, or a mixture thereof.
 13. Theformulation of claim 1, wherein said solubilizing agent comprises lessthan about 2 volume percent of said additive formulation for reducing:exhaust emissions, hydrocarbon emissions, or a mixture thereof.
 14. Theformulation of claim 1, wherein said nitroparaffin comprises less thanabout 10 volume percent of said formulation.
 15. A fuel for reducingemissions from a motor vehicle, comprising: an additive formulationcomprising: a nitroparaffin; a solubilizing agent comprising: relativelypolar and relatively non-polar ends selected from the group consistingof an ester compound, a simple ester compound; and an aromatichydrocarbon; said fuel resulting in reduced emissions relative to amotor fuel not comprising said additive formulation.
 16. The fuel ofclaim 15, wherein said solubilizing agent comprises an ester, simpleester, ester alcohol, simple ester alcohol, ester ether alcohol, simpleester ether alcohol, amino alkane, ester amine, or mixture thereof. 17.The fuel of claim 15, wherein said solubilizing agent comprises: anester alcohol, simple ester alcohol, ester ether alcohol, ester amine,or a mixture thereof.
 18. The fuel of claim 15, wherein saidnitroparaffin further comprises: a 1-nitropropane, 2-nitropropane,nitroethane, nitromethane, or a mixture thereof.
 19. The fuel of claim15, wherein said aromatic hydrocarbon comprises an aliphatic derivativeof benzene.
 20. The fuel of claim 15, wherein said aromatic hydrocarboncomprises: benzene, ethyl benzene, xylene, toluene, or a mixturethereof.
 21. A fuel for reducing emissions from a motor vehicle,comprising: an additive formulation comprising: a first component,comprising about 0 to 99 volume percent of 1-nitropropane,2-nitropropane, nitroethane, nitromethane, or a mixture thereof; asecond component, comprising the balance of the additive formulation,of: an ester alcohol, simple ester, ester ether alcohol, ester amine, ora mixture thereof; said additive formulation added to said fuel to afinal concentration of less than about 5 volume percent of said additivein said fuel; and said additive formulation for reducing one or more ofthe emissions comprising: total hydrocarbons, non-methane hydrocarbons,carbon monoxide, NO_(x), or ozone precursors.
 22. The fuel of claim 21,wherein said first component further comprises: 20 to 40 volume percentnitromethane, and 60 to 80 volume percent of: 1-nitropropane,2-nitropropane, nitroethane, or a mixture thereof.
 23. The fuel of claim21, further comprising an additive comprising toluene.
 24. The fuel ofclaim 21, further comprising an additive comprising less than 20 volumepercent toluene and less than 10 volume percent of said secondcomponent.
 25. The fuel of claim 15, wherein said additive formulationis adapted for use in a power unit comprising: a boiler, turbine, orinternal combustion engine.
 26. The fuel of claim 25, wherein saidinternal combustion engine comprises: a gasoline engine or a dieselengine.
 27. The fuel of claim 15, wherein said reduced emissionscomprise: carbon monoxide, NO_(x), total hydrocarbon, non-methanehydrocarbon, ozone precursors, or a mixture thereof.
 28. The fuel ofclaim 15, wherein said solubilizing agent comprises less than about 2volume percent of said additive formulation to reduce emissionscomprising: exhaust emissions, hydrocarbon emissions, or a mixturethereof.
 29. The fuel of claim 15, wherein said nitroparaffin comprisesless than about 10 volume percent of said formulation.
 30. An additiveformulation for motor fuels comprising: a nitroparaffin substantiallyfree from 2-nitropropane; and a solubilizing agent comprising less thanabout 10% of the final volume of said additive formulation; wherein saidsolubilizing agent is: an ester compound, a simple ester compound, esteralcohol, simple ester alcohol, ester ether alcohol, simple ester etheralcohol, an amino alkane compound or ester amine comprising at least onechemically relatively polar end and at least one chemically relativelynon-polar end; said fuel resulting in reduced emissions relative tomotor fuel not containing said additive.
 31. The formulation of claim30, wherein said nitroparaffin comprises: 1-nitropropane, nitroethane,nitromethane, or a mixture thereof.
 32. An additive formulation formotor fuels comprising: a first component, comprising about 0 to 99volume percent of 1-nitropropane, nitroethane, nitromethane, or amixture thereof; a second component, comprising substantially thebalance of the additive formulation, comprising a solubilizing agentcomprising at least one chemically relatively polar end and at least onechemically relatively non-polar end; said additive added to said fuel toa final concentration of less than about 5 volume percent of saidadditive in said fuel; and the additive formulation reducing emissionscomprising: total hydrocarbons, non-methane hydrocarbons, carbonmonoxide, NO_(x), ozone precursors, or a mixture thereof.
 33. Theformulation of claim 32, wherein said first component comprises: 20 to40 volume percent nitromethane, and 60 to 80 volume percent of one ormore nitroparaffin components, comprising: 1-nitropropane, nitroethane,or a mixture thereof.
 34. The formulation of claim 32, furthercomprising less than 20 volume percent of an aromatic hydrocarbon andless than 10 volume percent said solubilizing agent.
 35. An additiveformulation for motor fuels comprising: from about 10 to about 30 volumepercent nitromethane; from about 10 to about 30 volume percentnitroethane; from about 40 to about 60 volume percent 1-nitropropane;from about 2 to about 8 volume percent toluene; and from about 0.5 toabout 3 volume percent solubilizing agent, wherein said solubilizingagent comprises at least one chemically relatively polar end and atleast one chemically relatively non-polar end.
 36. The formulation ofclaim 35, further comprising: about 20 volume percent nitromethane,about 20 volume percent nitroethane, and about 60 volume percent1-nitropropane.
 37. The formulation of claim 35, further comprisingabout 10 volume percent toluene and about 2 volume percent of saidsolubilizing agent.
 38. The additive formulation of claim 30, furthercomprising an aromatic hydrocarbon.
 39. The formulation of claim 30,further comprising an aliphatic derivative of benzene.
 40. Theformulation of claim 38, wherein said aromatic hydrocarbon comprises:benzene, ethyl benzene, xylene, toluene, or a mixture thereof.
 41. Theformulation of claim 30, wherein said formulation is adapted for use ina power unit comprising: boiler, turbine, or internal combustion engine.42. The formulation of claim 30, wherein said at least one chemicallyrelatively polar end comprises: an ether group and/or an amine group.43. The formulation of claim 30, wherein said at least one chemicallyrelatively non-polar end comprises: a hydrocarbon group, an aromatichydrocarbon group, or an aliphatic hydrocarbon group.
 44. Theformulation of claim 30, wherein said solubilizing agent comprises: anester, an ester alcohol, a simple ester alcohol, a simple ether alcoholester, an ether, or an ester amine compound.
 45. The formulation ofclaim 44, wherein said ester is prepared by the reaction of an etheralcohol with a monobasic acid.
 46. The formulation of claim 44, whereinsaid ester is prepared by the reaction of an ether alcohol, an acidchloride, and an amine.
 47. The formulation of claim 30, wherein saidsolubilizing agent is an amino alkane compound.
 48. The formulation ofclaim 30, wherein said solubilizing agent is an amino alkane compound ofthe formula:

wherein R₁ is selected from the group consisting of: hydrogen, an alkylgroup, and an aryl group; wherein R₂ is selected from the groupconsisting of: hydrogen, an alkyl group, and an aryl group; and whereinn equals from one to eight.
 49. The formulation of claim 30 wherein saidreduced emissions comprise of: carbon monoxide, NO_(x), totalhydrocarbon, non-methane hydrocarbon, or ozone precursors.
 50. Theformulation of claim 30, wherein said solubilizing agent comprises lessthan about 2 volume percent of said additive formulation to reduce:exhaust emissions, hydrocarbon emissions, or a mixture thereof.
 51. Theformulation of claim 30, wherein said nitroparaffin comprises less thanabout 10 volume percent of said additive formulation.
 52. A method ofpreparing a fuel additive formulation, comprising: in a mixing vessel;adding about 1 part solubilizing agent comprising at least onechemically relatively polar end and at least one chemically relativelynon-polar end, selected from the group consisting of: an ester compound,and a simple ester compound; allowing said solubilizing agent to standfor 10 minutes at ambient temperature and pressure; adding about 10parts nitromethane to said solubilizing agent mixture; adding about 10parts nitroethane to said mixture; adding about 29 parts 1-nitropropaneto said mixture; aerating said mixture gently, through a narrow gaugetube at low pressure and ambient temperature; and storing the additive.53. The method of claim 52, further comprising adding about 5 partstoluene, prior to the step of allowing said solubilizing agent to stand.54. The additive made by the method of claim
 52. 55. A motor fuel,comprising an additive made by the method of claim
 52. 56. A motor fuel,comprising an additive made by the method of claim 52, at aconcentration of about 0.1 oz. of additive per gallon of motor fuel. 57.A fuel for vehicles, comprising an additive made by the method of claim52.
 58. A fuel for reducing emissions from a vehicle, comprising:formulating an additive comprising: nitroparaffin substantially freefrom 2-nitropropane; and solubilizing agent at a concentration of lessthan about 10% in said additive, wherein said solubilizing agentcomprises at least one chemically relatively polar end and at least onechemically relatively non-polar end; and adding said additive to saidfuel at a concentration of about 1-99 volume percent of said additive tosaid fuel.
 59. The fuel of claim 58, wherein said nitroparaffin furthercomprises: 1-nitropropane, nitroethane, nitromethane, or mixturethereof.
 60. A fuel for reducing emissions from a motor vehicle,comprising: formulating an additive comprising: a first component,comprising about 0 to 99 volume percent of 1-nitropropane, nitroethane,nitromethane, or a mixture thereof; a second component, comprisingsubstantially the balance of the additive formulation, comprising atleast one chemically relatively polar end comprising an ether group, andan amine group, and at least one chemically relatively non-polar end;said additive added to said fuel to a final concentration of less thanabout 5 volume percent of said additive in said fuel; and the additiveformulation reducing one or more emissions of: total hydrocarbons,non-methane hydrocarbons, carbon monoxide, NO_(x), and ozone precursors.61. The fuel of claim 60, wherein said first component furthercomprises: 20 to 40 volume percent nitromethane, and 60 to 80 volumepercent of 1-nitropropane, nitroethane, or a mixture thereof.
 62. Thefuel of claim 60, further comprising an additive comprising less than 20volume percent toluene and less than 10 volume percent said solubilizingagent.
 63. A fuel for reducing emissions from an automobile, comprising:formulating an additive comprising: from about 10 to about 30 volumepercent nitromethane; from about 10 to about 30 volume percentnitroethane; from about 40 to about 60 volume percent 1-nitropropane;from about 2 to about 8 volume percent toluene; from about 1 to about 3volume percent solubilizing agent, wherein said solubilizing agentcomprises at least one chemically relatively polar end selected from thegroup consisting of: an ether group and an amine group, and at least onechemically relatively non-polar end; and adding said additive to thefuel.
 64. The fuel of claim 63, further comprising: about 20 volumepercent nitromethane, about 20 volume percent nitroethane, and about 60volume percent 1-nitropropane.
 65. The fuel of claim 63, furthercomprising about 10 volume percent toluene and about 2 volume percent ofsaid solubilizing agent.
 66. The fuel of claim 58, further comprising anaromatic hydrocarbon.
 67. The fuel of claim 58, further comprising analiphatic derivative of benzene.
 68. The fuel of claim 66, wherein saidaromatic hydrocarbon comprises: benzene, ethyl benzene, xylene, ortoluene.
 69. The fuel of claim 58, wherein said formulation is adaptedfor use in a power unit comprising: boiler, turbine, or internalcombustion engine.
 70. The fuel of claim 58, wherein said at least onechemically relatively polar end comprises: an ether group and an aminegroup.
 71. The fuel of claim 58, wherein said at least one chemicallyrelatively non-polar end comprises: a hydrocarbon group, an aromatichydrocarbon group, or an aliphatic hydrocarbon group.
 72. The fuel ofclaim 58, wherein said solubilizing agent comprises: an ester alcohol, asimple ester alcohol, a simple ester ether alcohol, an ester aminecompound, or a mixture thereof.
 73. The fuel of claim 72, wherein saidester is prepared by the reaction of an ether alcohol with a monobasicacid.
 74. The fuel of claim 72, wherein said ester is prepared by thereaction of an ether alcohol, an acid chloride, and an amine.
 75. Thefuel of claim 58, wherein said solubilizing agent is an amino alkanecompound.
 76. The fuel of claim 58, wherein said solubilizing agent isan amino alkane compound of the formula:

wherein R₁ is selected from the group consisting of: hydrogen, an alkylgroup, and an aryl group; wherein R₂ is selected from the groupconsisting of: hydrogen, an alkyl group, and an aryl group; and whereinn equals from one to eight.
 77. The fuel of claim 69, wherein saidinternal combustion engine is selected from the group consisting of: agasoline engine and a diesel engine.
 78. The fuel of claim 58, whereinsaid reduced emissions comprise: carbon monoxide, NO_(x), totalhydrocarbon, non-methane hydrocarbon, ozone precursors, or a mixturethereof.
 79. The formulation of claim 58, wherein said solubilizingagent comprises less than about 2 volume percent of said additiveformulation to reduce: exhaust emissions and/or hydrocarbon emissions.80. The formulation of claim 58, wherein said nitroparaffin comprisesless than about 10 volume percent of said formulation.
 81. Theformulation of claim 1 wherein said chemically polar end comprises anether group, an ester group or an amino group.
 82. The formulation ofclaim 1 wherein said chemically nonpolar end comprises a hydrocarbongroup.
 83. The formulation of claim 30 wherein said solubilizing agentcomprises an ester compound, simple ester compound, ester alcohol,simple ester alcohol, ester ether alcohol, simple ester ether alcohol,amino alkane compound, ester amine, or a mixture thereof.
 84. The methodof claim 52 wherein said solubilizing agent comprises: an estercompound, simple ester compound, ester alcohol, simple ester alcohol,ester ether alcohol, simple ester ether alcohol, amino alkane compound,ester amine, or a mixture thereof.
 85. The fuel for reducing emissionsfrom a vehicle according to claim 58, wherein said solubilizing agentcomprises: an ester compound, simple ester compound, ester alcohol,simple ester alcohol, ester ether alcohol, simple ester ether alcohol,amino alkane compound, ester amine, or a mixture thereof.